Insects and spiders share all of the following characteristics except O A chitin
ID: 201698 • Letter: I
Question
Insects and spiders share all of the following characteristics except O A chitin exoskeleton OB chelicera OC open circulatory system D jointed appendages QUESTION 2 How do ecdysozoans increase in size? OA They molt and replace their cutides O B. They use water to swell their exoskeletons. OC They use water to swell their epidermises OD They molt and replace their endoskeletons QUESTION 3 A foot, mantle and visceral mass of internal organs are all found in which organism? O A. Mollusks B. Annelids C Arthropods O D Flatworms QUESTION 4 Trilobites are the earliest known arthropods to have had jointed appendages True False QUESTION 5 All of the following are characteristics of flatworms except A diliated 8 cephalization O C Small and flat OD contains coelomExplanation / Answer
1. Both insects and spiders have open circulatory system. They lack true blood or even veins to transport it. Instead, they have hemolymph. Both have a chitin exoskeleton and joined appendages.
Chelicerae are appendages that are present in front of the mouth used to crush prey. The basal segment in spider chelicerae contains venom sacs. The fang is used to inject venom in the prey. Insects lack chelicerae. Instead, they have mandibles. They are used to grasp, crush, or cut the food. They are also used to defend against predators.
Right option is B. Chelicera
2. Ecdysozoans increase in size by molting their exoskeleton. The epidermis secretes a molting fluid that digest the bottom layer of cuticle. The epidermis secretes a new epicuticle adding an inner layer beneath it. Loss of the old inner layer is followed by swelling of its body due to intake of water or air. As a result, the new cuticle expands and swells. Thus, the outer layer is broken at a weak point. The organism will then expand its body and harden the outer cuticle layer.
Right choice is A. they molt and replace their cuticles.
3. All mollusks have a foot, mantle and visceral mass. Molluscs include snails, slugs, clams, scallops, oysters, cuttlefish, squid, octopus. A single muscular ventral foot covers the underside of the body. Mantel is the dorsal body wall covering the visceral mass and secretes the shell. Visceral mass contains organs of digestive system, reproduction, excretion and circulation.
Right choice is A. Mollusks.
As per Chegg’s rules, only one question needs to be answered.